For example, from the document DE 10 2010 024 147 a two-speed transmission and a method for controlling a two-speed transmission are known. The transmission, which can be partially power shifted with an electric drive input, comprises a friction clutch and an interlocking clutch. Because of these, an overdrive upshift from the first gear to the second gear and an overdrive downshift from the second to the first gear cannot be carried out as power shifts.
During an overdrive shift, the vehicle is in overdrive operation and consequently the vehicle is being braked by the electric machine and recuperation is taking place. For example when driving downhill, despite the negative motor torque of the electric machine the vehicle's speed can increase. To avoid exceeding a specified maximum rotational speed of the electric machine, for example a 1-2 overdrive upshift is required. However, in this situation the traction-force-interrupted gearshift has the disadvantage that due to the sudden acceleration the driver is taken by surprise, which has a comfort-reducing effect. To prevent this, during the shifting process, the service brake can be actuated so that the vehicle does not accelerate during the shifting process. This, however, has the disadvantage of requiring elaborate control measures since the electric machine and the service brake have to be precisely coordinated with one another.